PENGUKURAN PANJANG GELOMBANG DENGAN TEKNIK DIFRAKSI FRAUNHOFER MENGGUNAKAN CELAH SEMPIT BERBENTUK LINGKARAN

Abstract

The research study of Fraunhofer diffraction studying pattern of Fraunhofer diffraction by using narrow circular aperture to determine wavelength of monochromatic light source use principle of Fraunhofer diffraction. With variable radius of bold pattern ring of to-n to bold of center ( n R ) what formed by as effect of source distance to screen (L) at circular aperture. Light source that used are He-Ne Laser with wavelength 633 nm, and red diode laser with wavelength 630-680 nm and output power 1 mW. He-Ne laser is used to calibrate the aperture diameter, the value that found his used to determine red diode laser wavelength. The circular aperture used with diameters 0,462 mm, and 0,575 mm. From research result that proportional graph inclination with wavelength. From research result wavelength for red dioda laser l = (679 ± 16) nm.